Gamma-Ray Telescopes

1. Gamma-Ray Telescopes

2. Brief History of Gamma Ray Astronomy 0 2008 Fermi (GLAST): All-sky monitoring of the MeV – GeV sky every 3 hr with sensitivity a factor of > 10 better than EGRET. 2004 Swift: Dedicated g-ray burst mission: prompt X-ray/optical follow-up; arcsecond localization of GRBs 2002 INTEGRAL: Major advances in high-resolution imaging and spectroscopy of Galactic g-ray sources 1997 BeppoSAX: First high-precision localization of g-ray bursts; cosmological origin of GRBs established 1991 CGRO: First all-sky survey of the g-ray sky; major discoveries in all areas of g-ray astronomy; g-ray astronomy becomes an integral part of astronomy 1989 SIGMA: First high-resolution images (13’) in hard X-rays / soft g-rays 1987 Whipple (ACT): First credible detection of a TeV source (Crab Nebula) 1981 SMM: Studies of solar flare g-ray emission; 56Co-lines from SN 1987A 1979 HEAO-3: Discovery of radioactive 26Al emission in the Milky Way 1975 COS-B: First detailed g-ray map of the Milky Way with 24 point sources 1972 SAS-2: First high-energy g-ray images; discovery of Geminga pulsar 1968 OSO-3: Discovery of > 100 MeV g-ray emission from the Milky Way 1967 VELA satelllites: Discovery of g-ray bursts (not published until 1973) 1961 EXPLORER-II: First detection of high-energy g-rays from space

3. 1) The Compton Gamma Ray Observatory (CGRO) 0 (1991 – 2000) Oriented Scintillation-Spectrometer Experiment (OSSE): ~ 0.1 – 10 MeV Compton Telescope (COMPTEL): ~ 1 – 30 MeV Energetic Gamma-Ray Experiment Telescope (EGRET): pair conversion telescope, ~ 20 MeV – 30 GeV Burst and Transient Source Experiment (BATSE): 0.015 – 110 MeV

4. 2) The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) 0 Launched 2002 Two g-ray telescopes: Imager on Board the INTEGRAL Satellite (IBIS), optimized for high spatial resolution; Spectrometer on INTEGRAL (SPI), optimized for high spectral resolution. Energy range: ~ 20 keV – 8 MeV Both use coded-mask technique for imaging.

5. 3) AGILE(Astro-rivelatore Gamma a Immagini LEggero) Italian gamma-ray satellite mission; launched April 23, 2007 Similar technology and capabilities as EGRET, intended to bridge the gap between EGRET and Fermi (GLAST) Two instruments: Gamma-Ray Imaging Detector (GRID): SuperAGILE: 30 MeV – 50 GeV 18 – 60 keV

6. 4) The Fermi Gamma-Ray Space Telescope (formerly: Gamma Ray Large Area Space Telescope (GLAST) 0 Launched June 11, 2008 Similar technology as EGRET (pair conversion), but much improved sensitivity, large field of view (~ p sr), and slightly extended energy range (~ 20 MeV – 300 GeV). Will operate in constant slewing mode to survey the sky for flaring high-energy g-ray sources: One full-sky scan every 3 hr.

7. 0 Fermi Two main science instruments: • LAT (Large Area Telescope) • GBM (GLAST Burst Monitor)

8. The Large Area Telescope (LAT) 0 Pair Conversion Telescope

9. The LAT First-Light All-Sky Map All-Sky Map

10. The GLAST Burst Monitor (GBM) 0 All-sky Monitor optimized to detect X-ray / soft g-ray flashes (~ 8 keV – 30 MeV) Source localization to < 15o

11. 5) Atmospheric Cherenkov Telescopes 0